1. Field of the Disclosure
The present disclosure relates to a feed tray that is fitted to a recording apparatus while accommodating a stack of multiple sheets and that is provided for feeding each sheet to a recording unit of the recording apparatus via a feed roller.
2. Description of the Related Art
Generally, the aforementioned feed tray has a box-shaped tray body having an upper opening so as to accommodate therein a stack of multiple sheets.
The tray body is provided with a trailing-edge positioning plate for positionally regulating the trailing edges of the sheets and movable side plates for positionally regulating the side edges of the sheets. The downstream side, in the feeding direction, of a bottom plate of the tray body is provided with a hole into which a sheet biasing member disposed in the recording apparatus can be inserted when the feed tray is fitted to the recording apparatus.
Furthermore, a tray plate is disposed on the bottom plate of the tray body in a pivotable manner so as to bring the downstream side of the sheets into pressure contact with a feed roller in the recording apparatus. The tray plate is a substantially rectangular thin plate that at least supports the leading edges, located at the downstream side in the feeding direction, of the sheets stacked and accommodated in the tray body. The rear end of the tray plate at the upstream side is supported by the upstream side of the bottom plate of the tray body relative to the aforementioned hole so that the front end of the tray plate at the downstream side is rotatable upward.
Furthermore, a cover is disposed on the tray body. The cover includes a first cover that is fixed so as to cover an area excluding an open area (referred to as “feed open area” hereinafter) of the tray body disposed facing the feed roller of the recording apparatus when the feed tray is fitted to the recording apparatus, and a second cover that is fixed so as to cover the feed open area when the feed tray is detached from the recording apparatus, thereby covering the entire opening of the tray body together with the first cover. The feed open area is located at the downstream side of the opening of the tray body.
In the feed tray in the related art, the sheets are stacked and placed on the inner surface of the tray body so as to be accommodated therein while the area excluding the feed open area of the tray body is covered by the cover (first cover). Then, when the end with the feed open area is fitted to one side of the recording apparatus (such that the feed tray extends outward from the recording apparatus and is supported in a cantilevered manner), a feed motor is driven so that the sheet biasing member is inserted into the tray body through the hole. Thus, the sheet biasing member rotates and biases the front end of the tray plate upward about the rear end of the tray plate acting as a pivot axis, so that the sheets placed on the tray plate are brought into pressure contact with the feed roller through the feed open area. Consequently, the uppermost sheet is brought into pressure contact with the lower side of the feed roller. When the feed roller is rotationally driven in this state, a frictional force between the feed roller and the uppermost sheet causes the sheet to become separated from the remaining sheets disposed therebelow, whereby the uppermost sheet is delivered (fed) from the tray body toward a printing position of the recording apparatus (for example, see Japanese Unexamined Patent Application Publication No. 2002-332126).
Generally, sheets that are formed by unwinding a large-diameter roll of wide roll paper, whose print surface faces inward, and cutting the roll paper into individual sheets with predetermined dimensions tend to curl in the longitudinal direction of the roll paper (i.e., the direction in which the roll paper was wound in a roll) depending on storage conditions.
In the feed tray in the related art having the fixed cover and fitted to the recording apparatus while accommodating a stack of multiple sheets, since the depth of the tray body is not adjustable, if such curled sheets are to be accommodated therein, it is necessary to remove some sheets that are equivalent to the height of the curl. For this reason, the feed tray can only accommodate a certain number of sheets that is smaller than a predetermined maximum number of sheets that can be accommodated in the feed tray. For example, if a set of 18 thick sheets P are curled, the number of sheets equivalent to the height of the curl would need to be removed, as shown in FIG. 6B, even though the feed tray is normally capable of accommodating all of the sheets if they were not curled, as shown in FIG. 6A. If the cover is forcedly fixed to the tray body by pressing on the curled sheets without removing any sheets, sliding friction between the cover and the sheet being conveyed would increase, making it difficult to perform a smooth feeding process and thus resulting in a feed error, such as a state where the sheet is not conveyed.
If the tray body is designed with a plenty of depth so as to be always capable of accommodating the same number of sheets, the feed tray would naturally become large in size, which is against the demands for size reduction and thickness reduction of the recording apparatus.
Furthermore, if the sheet to be fed for recording is curled in the width direction, the sheet may partially abut or slide on the lower side of the cover (first cover) or the edges of the feed open area, sometimes inhibiting a stable sheet conveying process. Therefore, for example, in a feed tray for a recording apparatus in which sheets whose side edges, in the width direction, tend to curl upward from the print surface (upper surface) relative to the middle are expected to be used as sheets to be fed for recording, an edge of the cover proximate to the aforementioned opening is formed such that the sides thereof in the width direction are gradually curved away from the opening in plan view relative to the middle so as to form a clearance (slide avoiding section) for reducing contact (sliding) between the opposite side edges of the curled sheet and the cover. This prevents the inhibition of the sheet conveying process caused by the sheet abutting on the cover.
However, the feed tray having the clearance in the cover has problems in that, when the clearance is located outside the recording apparatus in a state where the feed tray is fitted to the recording apparatus, dust and foreign matter (simply referred to as “foreign matter” hereinafter) can easily enter the feed tray through the clearance, or the accommodated sheets exposed through the clearance may become discolored due to exposure to sunlight. In addition, when printing operation is performed in a state where foreign matter is adhered to a sheet, not only is the print result is adversely affected, but also the thermal head may break as a result of the foreign matter adhering to the thermal head.
The present invention provides a feed tray that allows for a stable sheet conveying process regardless of whether or not a sheet is curled, that can accommodate a maximum number of sheets even if they are curled, without being increased in thickness, and that can prevent foreign matter from entering the feed tray as well as preventing discoloration of the sheets caused by exposure to sunlight in a state where the feed tray is fitted to a recording apparatus.